Angry Editor :I am not aware of any US/British split on this one. I think such a disagreement would be less likely with a word used globally in the last couple of decades. What do you think?

I think the hyphen better emphasizes the “electronic” part. I think “email” seems a little lazy. I mean, what the heck are hyphens for if people don’t use them. For example, merry-go-round and editor-in-chief would be merrygoround and editorinchief, hard to read….

and another resource-Wikipedia
Electronic mail, often abbreviated as email, e.mail or e-mail, is a method of exchanging digital messages, designed primarily for human use.
http://en.wikipedia.org/wiki/E-mail

Actually, I dont think it’s a serious problem, I think both are fine-email or e-mail.